Recently, as a next generation energy, a fuel cell device is proposed in which a fuel cell stack (device) is accommodated in a container, the fuel cell stack having a row of a plurality of fuel cells that can obtain electrical power using a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (typically, air) (see Japanese Unexamined Patent Publication JP-A 2003-308857, for example).
In this sort of fuel cell device, a plurality of fuel cells are arranged upright and are electrically connected via a current-collecting member interposed between adjacent fuel cells, fuel cell stack-supporting members are arranged via end current-collecting members on both sides in the arrangement direction, a fuel cell stack device in which the fuel cells in this state are fixed to a manifold for supplying a fuel gas and the like to the fuel cells is accommodated in an container, and the fuel cell stack device is surrounded by a heat insulator such that radiant heat generated by the fuel cell stack device producing electric power is not transmitted to the outside.
FIG. 12A is a side view showing a conventional fuel cell stack device 51, and FIG. 12B is a plan view extracting part of FIG. 12A. In this sort of fuel cell stack device 51, a plurality of columnar fuel cells 53 are arranged upright via a current-collecting member 54a interposed therebetween, conductive members 55 are arranged via end current-collecting members 54b on both sides in the arrangement direction, and, in this state, the lower ends of the fuel cells 53 and the conductive members 55 are fixed to a manifold 57 for supplying a reactant gas (a fuel gas and the like).
FIG. 13 is a perspective view extracting the conductive member 55 forming the conventional fuel cell stack device 51 shown in FIG. 12A, and the conductive member includes a flat plate portion 65 and a pair of side plate portions 66 that are bent from both edges of the flat plate portion 65.
When the fuel cell device that accommodates the fuel cell stack device is operated, the temperature of the fuel cells increases. Here, in the case where the coefficient of thermal expansion varies between constituent elements forming the fuel cells, the fuel cells may be warped. When this sort of warping occurs, stress is generated in the fuel cells. Here, in a fuel cell stack in which a plurality of columnar fuel cells are arranged upright, intensive stress may be generated particularly in fuel cells on end sides in the warping direction of the fuel cells, and these fuel cells may be damaged.
Here, the conductive member 55 as shown in FIG. 13 has high rigidity, and a firm structure is obtained. Thus, in the case where the conductive member 55 is used, fuel cells on end sides in the arrangement direction of the fuel cells may be damaged.
Accordingly, it is conceivable that elastically deformable members that can be deformed flexibly following the deformation (warping) of the fuel cells are arranged on both end sides of the fuel cell stack, thereby relaxing stress generated in the fuel cells, and suppressing a damage to the fuel cells.
Furthermore, when a fuel cell device that accommodates such a fuel cell stack device is assembled, a heat insulator is disposed around the fuel cell stack device in order to suppress transmission, to the outside, of radiant heat generated by the fuel cells producing electric power.
However, in the case where the heat insulator is disposed close to the fuel cell stack device having an elastically deformable conductive member, the conductive member deformed following the deformation (warping) of the fuel cells may be brought into contact with the heat insulator, stress generated in the fuel cells may not be relaxed, and a damage to the fuel cells may not be suppressed.
Furthermore, it is also conceivable that the heat insulator is disposed with a predetermined spacing interposed from the elastically deformable conductive member assuming the length by which the conductive member is deformed, but, in this case, positional adjustment of the heat insulator is difficult. Furthermore, there is a problem in that an assembly process of a fuel cell device that accommodates a fuel cell stack device becomes complex.